Add a reference name for the ReviewRequestFieldSetsHook docs.
Add a reference name for the ReviewRequestFieldSetsHook docs.

This will be used to allow the release notes to link to the docs.

reviewboard/reviewboard,1tush/reviewboard,1tush/reviewboard,beol/reviewboard,1tush/reviewboard,bkochendorfer/reviewboard,chipx86/reviewboard,davidt/reviewboard,sgallagher/reviewboard,1tush/reviewboard,brennie/reviewboard,reviewboard/reviewboard,bkochendorfer/reviewboard,1tush/reviewboard,1tush/reviewboard,davidt/reviewboard,brennie/reviewboard,custode/reviewboard,custode/reviewboard,beol/reviewboard,beol/reviewboard,KnowNo/reviewboard,KnowNo/reviewboard,sgallagher/reviewboard,davidt/reviewboard,sgallagher/reviewboard,chipx86/reviewboard,brennie/reviewboard,chipx86/reviewboard,chipx86/reviewboard,1tush/reviewboard,reviewboard/reviewboard,bkochendorfer/reviewboard,beol/reviewboard,1tush/reviewboard,davidt/reviewboard,KnowNo/reviewboard,bkochendorfer/reviewboard,sgallagher/reviewboard,brennie/reviewboard,custode/reviewboard,reviewboard/reviewboard,custode/reviewboard,KnowNo/reviewboard,1tush/reviewboard